[U-Boot] [PATCH v3 8/9] tegra: i2c: Enable new CONFIG_SYS_I2C framework

[Heiko Schocher]

Hello Stephen

Am 30.07.2013 20:56, schrieb Stephen Warren:
> On 07/29/2013 10:28 PM, Heiko Schocher wrote:
>> Hello Stephen,
>>
>> Am 29.07.2013 18:12, schrieb Stephen Warren:
>>> On 05/04/2013 06:01 AM, Heiko Schocher wrote:
>>>> From: Simon Glass<sjg at chromium.org>
>>>>
>>>> This enables CONFIG_SYS_I2C on Tegra, updating existing boards and
>>>> the Tegra
>>>> i2c driver to support this.
>>>
>>> Heiko, the latest U-Boot tree hangs during boot on Tegra, and "git
>>
>> :-(
>>
>> Could you enable debug printf?
>>
>>> bisect" points at this patch. Olof reported the issue to me.
>>
>> Thanks!
>>
>>> Can you take a look at the code and see what might be wrong? Thanks.
>>
>> Yep.
>>
>>> I suspect some kind of initialization ordering issue, since the boot
>>> messages are:
>>>
>>> -----
>>> U-Boot SPL 2013.07-rc3-00038-g880540d (Jul 29 2013 - 10:04:37)
>>> U-Boot 2013.07-rc3-00038-g880540d (Jul 29 2013 - 10:04:37)
>>>
>>> TEGRA30
>>> Board: NVIDIA Beaver
>>> I2C:   Caller requested bad clock: periph=-49, parent=2
>>> -----
>>>
>>> ... and that "bad clock" message implies to me that the I2C driver is
>>> initializing before it has parsed the correct clock ID out of device
>>> tree.
>>
>> Hmm... looking in the patch ... I can see nothing which changes
>> some initializing order ...
>>
>> @Simon: Do you have an idea?
>>
>> just found some wrong settings for tegra30:
>>
>> In include/configs/tegra30-common.h:
>> /* Total I2C ports on Tegra30 */
>> #define TEGRA_I2C_NUM_CONTROLLERS       5
>>
>> README says:
>>                 - drivers/i2c/tegra_i2c.c:
>>                  - activate this driver with CONFIG_SYS_I2C_TEGRA
>>                  - This driver adds 4 i2c buses with a fix speed from
>>                    100000 and the slave addr 0!
>
> I think that's just stale documentation; Tegra20 had just 4 I2C
> controllers, and the docs probably weren't updated for Tegra30 which has 5.
>
>> end yes, in the i2c driver are only 4 ports activated ... this
>
> I don't see any limit in the driver; everything seems to use
> TEGRA_I2C_NUM_CONTROLLERS.
>
>> should be changed ... but I think, this has nothing to do with
>> your problem ... but try to add in the i2c driver one more i2c adapter
>> for the case TEGRA_I2C_NUM_CONTROLLERS>  4

As I wrote here, add (at the end of the file):

#if TEGRA_I2C_NUM_CONTROLLERS > 4
U_BOOT_I2C_ADAP_COMPLETE(tegra4, tegra_i2c_init, tegra_i2c_probe,
                          tegra_i2c_read, tegra_i2c_write,
                          tegra_i2c_set_bus_speed, 100000, 0, 4)
#endif

bye,
Heiko